Question

The covalent compound HCl has partial ionic character because:
A. Electronegativity of hydrogen is greater than that of Chlorine
B. Electronegativity of hydrogen is same as that of Chlorine
C. Electronegativity of hydrogen is less than that of Chlorine
D. Hydrogen is a metal while Chlorine is a non-metal

Answer 1

Hint: Hydrogen shares its electron with Chlorine, and hence they make a covalent compound HCl. All covalent bonds have a certain ionic character as stated by Fajan’s rule. This is determined by factors such as polarizing power of cation, polarizability of anion, etc.

Complete step by step answer:
Hydrogen Chloride, i.e. HCl is a covalent compound because it is made by sharing one electron each between hydrogen and chlorine. It therefore forms a single form. The structure of HCl is as given below -

Chlorine is a halogen and has an electronegativity of 3.16, whereas electronegativity of Hydrogen is 2.2. Due to this, chlorine has a tendency to ‘pull’ both the electrons in the covalent bond towards itself. Chlorine, therefore, develops a slight negative charge and hydrogen develops a slightly positive charge.
As a result of this, the covalent bond between Hydrogen and Chlorine develops a partial ionic character.
Therefore, the answer is – option (c) – The covalent compound HCl has partial ionic character because electronegativity of hydrogen is less than that of Chlorine.

Additional Information:
Fajan’s rule states that no ionic or covalent bond is perfectly ionic or covalent. “It is used to predict whether a chemical bond will be covalent or ionic, and depend on the charge on the cation and the relative sizes of the cation and anion.”

Note: There are two major types of chemical bonds –
Intermolecular
It is further divided into –
Ionic / electrovalent
Covalent
Coordinate
Metallic
Intramolecular
It is further divided into –
Vander Wall force
Hydrogen bonding